CYPRIAN, O. S., ANDREW MASIBAYI, and N. B. OKELO. “ON THE CONVEXITY OF THE JOINT ESSENTIAL NUMERICAL RANGES”. IJRDO -JOURNAL OF MATHEMATICS 1, no. 1 (May 31, 2015): 23-28. Accessed May 16, 2024. https://www.ijrdo.org/index.php/m/article/view/2399.